#include<bits/stdc++.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <pi, int>
#define vi vector <int>
const ll mod = 1000000007;
#define int ll
int n, m, k;
string s[101];
int gcd(int a, int b){
if(a==0) return b;
else return gcd(b%a, a);
}
int32_t main(){
ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
cin>>n>>m>>k;
if(n<=100 && m<=100){
for(int i=1; i<=n; i++){
cin>>s[i];
}
for(int i=1; i<=n; i++){
bool ctrl=1;
for(int j=1; j<=n; j++){
if(j!=i){
int dif=0;
for(int ix=0; ix<m; ix++)
if(s[i][ix]!=s[j][ix]) dif++;
if(dif!=k){
ctrl=0;
continue;
}
}
}
if(ctrl) return cout<<i, 0;
}
}
}
